Device and method in wireless communication system

ABSTRACT

Disclosed is a device and a method in a wireless communication system, and the device comprises: a transmitting unit configured to transmit a first allocation signal synthesized by use of the superimposed coding to plenty of user equipment at least comprising a first and a second user equipment, and the first allocation signal at least comprising a first power signal part for the first user equipment and a second power signal part for the second user equipment; a receiving unit configured to receive at least a feedback retransmission request from the first and the second user equipment; and a processing unit configured to process the first and the second power signal parts with a preset processing coefficient to obtain a second allocation signal in response to the retransmission request, and the transmitting unit is further configured to transmit the second allocation signal to the first and the second user equipment which merge the first and the second allocation signals in order to separately obtain the data for the first and the second user equipment.

This application claims the priority of Chinese Patent Application No.201510501585.X, titled “DEVICE AND METHOD IN WIRELESS COMMUNICATIONSYSTEM” and filed with the Chinese State Intellectual Property Office onAug. 14, 2015, which is incorporated herein by reference in itsentirety.

FIELD

The present disclosure relates to the field of wireless communicationtechnology, and particularly relates to a device and a method in awireless communication system for eliminating interfering signals ofmultiple transmissions in a wireless communication system for amulti-user superposition transmission (MUST), to effectively improve adata reception success rate and throughput of multi-stream superpositiontransmission.

BACKGROUND

In an existing wireless communication system in which the multi-usersuperposition transmission is adopted, a base station superposes datastreams of different users with different transmission power beingallocated based on channels of the users, a user equipment eliminatesinterference from other user equipment using for example a successiveinterference cancellation mechanism, and extracts a target data streamfrom the received superposed data stream. If extraction of the targetdata stream is failed, the user equipment may inform the base stationthat the target data stream is not extracted, and the base station maysimply retransmit the data stream. However, if the retransmission isalso superposition transmission, interference from other user equipmentstill exists in the retransmitted data stream. In this case, if the userequipment simply superposes the re-received data stream with thepreviously-received data stream to enhance the data stream, althoughpower of the received signal is enhanced, power of the interferingsignal may be also enhanced, resulting in a possibility of extractingthe target data stream by retransmission is reduced.

SUMMARY

A brief summary of the disclosure will be given below to provide basicunderstanding of some aspects of the disclosure. However, it shall beappreciated that this summary is neither exhaustively descriptive of thedisclosure nor intended to define essential or important components orthe scope of the disclosure but is merely for the purpose of presentingsome concepts of the disclosure in a simplified form and hereby acts asa preamble of more detailed descriptions which will be presented later.

In view of the above problems, an object of the present disclosure is toprovide a device and method in a wireless communication system, whichovercomes the shortcomings in the conventional technology above and canreduce interference from other users by performing predeterminedprocessing for the retransmitted signal, thereby improving a datareception success rate and throughout of the multi-stream superpositiontransmission.

A device in a wireless communication system is provided in an aspect ofthe present disclosure, which includes: a transmitting unit configuredto transmit a first allocation signal superposed using superpositioncoding to a plurality of user equipment comprising at least a first userequipment and a second user equipment, wherein the first allocationsignal comprises at least a first power signal portion for the firstuser equipment and a second power signal portion for the second userequipment; a receiving unit configured to receive a retransmissionrequest fed back from at least one of the first user equipment and thesecond user equipment; and a processing unit configured to process, inresponse to the retransmission request, the first power signal portionand the second power signal portion with predetermined processingcoefficients to obtain a second allocation signal, wherein thetransmitting unit is further configured to transmit the secondallocation signal to the first user equipment and the second userequipment, so that the first user equipment and the second userequipment merge the first allocation signal and the second allocationsignal to obtain data for the first user equipment and data for thesecond user equipment.

According to a preferred embodiment of the present disclosure, in themerged first allocation signal and second allocation signal, one of thefirst power signal portion and the second power signal portion isweakened or eliminated.

According to another preferred embodiment of the present disclosure, theprocessing unit is further configured to adjust a transmission power ofat least one of the first power signal portion and the second powersignal portion to obtain the second allocation signal.

According to another preferred embodiment of the present disclosure, thetransmitting unit is further configured to transmit to the first userequipment and the second user equipment a merging indication indicatinghow to merge, so that the first user equipment and the second userequipment merge the first allocation signal and the second allocationsignal based on the merging indication.

According to another preferred embodiment of the present disclosure, themerging indication is contained in high layer signaling or physicallayer signaling.

According to another preferred embodiment of the present disclosure, themerging indication is to perform merging to enhance a higher one of thefirst power signal portion and the second power signal portion.

According to another preferred embodiment of the present disclosure, themerging indication is to perform merging to respectively enhance thefirst power signal portion for the first user equipment and the secondpower signal portion for the second user equipment.

According to another preferred embodiment of the present disclosure, thepredetermined processing coefficients are determined based on a Hadamardmatrix.

A device in a wireless communication system is further provided inanother aspect of the present disclosure, which includes: a receivingunit configured to receive a first allocation signal from a basestation, wherein the first allocation signal is superposed usingsuperposition coding and comprises at least a first power signal portionfor a first user equipment and a second power signal portion for asecond user equipment; a processing unit configured to obtain data forthe first user equipment according to the first allocation signal; and atransmitting unit configured to transmit, in a case that the processingunit fails to obtain the data for the first user equipment according tothe first allocation signal, a retransmission request to the basestation, wherein the receiving unit is further configured to receive asecond allocation signal from the base station, the second allocationsignal being obtained by processing, by the base station, the firstpower signal portion and the second power signal portion withpredetermined processing coefficients in response to the retransmissionrequest fed back from at least one of the first user equipment and thesecond user equipment, and wherein the processing unit is furtherconfigured to merge the first allocation signal and the secondallocation signal to obtain the data for the first user equipment.

A device in a wireless communication system is further provided inanother aspect of the present disclosure, which includes: a receivingunit configured to receive a first allocation signal, wherein the firstallocation signal comprises at least a first power signal portion and asecond power signal portion transmitted respectively by a first userequipment and a second user equipment on same first radio transmissionresources; a processing unit configured to obtain data from the firstuser equipment and data from the second user equipment according to thefirst allocation signal; and a transmitting unit configured to transmit,in a case that the processing unit fails to obtain the data from atleast one of the first user equipment and the second user equipmentaccording to the first allocation signal, a retransmission request tothe first user equipment and the second user equipment, wherein thereceiving unit is further configured to receive a second allocationsignal, the second allocation signal comprising at least a third powersignal portion and a fourth power signal portion transmittedrespectively by the first user equipment and the second user equipmenton same second radio transmission resources in response to theretransmission request, the third power signal portion and the fourthpower signal portion being obtained by respectively processing the firstpower signal portion and the second power signal portion withpredetermined processing coefficients, and wherein the processing unitis further configured to merge the first allocation signal and thesecond allocation signal to obtain the data from the first userequipment and the data from the second user equipment.

A device in a wireless communication system is further provided inanother aspect of the present disclosure, which includes: a transmittingunit configured to transmit a first power signal portion to a basestation at a first transmission power on first radio transmissionresources, which are the same as radio transmission resources on which asecond user equipment transmits a second power signal portion; areceiving unit configured to receive a retransmission request from thebase station; and a processing unit configured to process, in responseto the retransmission request, the first power signal portion with apredetermined processing coefficient to obtain a third power signalportion, wherein the transmitting unit is further configured to transmitthe third power signal portion to the base station at a thirdtransmission power on second radio transmission resources, which are thesame as radio transmission resources on which the second user equipmenttransmits a fourth power signal portion, the fourth power signal portionbeing obtained by processing, by the second user equipment, the secondpower signal portion with a predetermined processing coefficient inresponse to the retransmission request.

A method in a wireless communication system is further provided inanother aspect of the present disclosure, which includes: a transmittingstep of transmitting a first allocation signal superposed usingsuperposition coding to a plurality of user equipment comprising atleast a first user equipment and a second user equipment, wherein thefirst allocation signal comprises at least a first power signal portionfor the first user equipment and a second power signal portion for thesecond user equipment; a receiving step of receiving a retransmissionrequest fed back from at least one of the first user equipment and thesecond user equipment; and a processing step of processing, in responseto the retransmission request, the first power signal portion and thesecond power signal portion with predetermined processing coefficientsto obtain a second allocation signal, wherein the transmitting stepfurther comprises transmitting the second allocation signal to the firstuser equipment and the second user equipment, so that the first userequipment and the second user equipment merge the first allocationsignal and the second allocation signal to obtain data for the firstuser equipment and data for the second user equipment.

A method in a wireless communication system is further provided inanother aspect of the present disclosure, which includes: a receivingstep of receiving a first allocation signal from a base station, whereinthe first allocation signal is superposed using superposition coding andcomprises at least a first power signal portion for a first userequipment and a second power signal portion for a second user equipment;a processing step of obtaining data for the first user equipmentaccording to the first allocation signal; and a transmitting step oftransmitting, in a case that the data for the first user equipment isnot obtained according to the first allocation signal, a retransmissionrequest to the base station, wherein the receiving step furthercomprises receiving a second allocation signal from the base station,the second allocation signal being obtained by processing, by the basestation, the first power signal portion and the second power signalportion with predetermined processing coefficients in response to theretransmission request fed back from at least one of the first userequipment and the second user equipment, and wherein the processing stepfurther comprises merging the first allocation signal and the secondallocation signal to obtain the data for the first user equipment.

A method in a wireless communication system is further provided inanother aspect of the present disclosure, which includes: a receivingstep of receiving a first allocation signal, wherein the firstallocation signal comprises at least a first power signal portion and asecond power signal portion transmitted respectively by a first userequipment and a second user equipment on same first radio transmissionresources; a processing step of obtaining data from the first userequipment and data from the second user equipment according to the firstallocation signal; and a transmitting step of transmitting, in a casethat the data from at least one of the first user equipment and thesecond user equipment is not obtained according to the first allocationsignal, a retransmission request to the first user equipment and thesecond user equipment, wherein the receiving step further comprisesreceiving a second allocation signal, the second allocation signalcomprising at least a third power signal portion and a fourth powersignal portion transmitted respectively by the first user equipment andthe second user equipment on same second radio transmission resources inresponse to the retransmission request, the third power signal portionand the fourth power signal portion being obtained by respectivelyprocessing the first power signal portion and the second power signalportion with predetermined processing coefficients, and wherein theprocessing step further comprises merging the first allocation signaland the second allocation signal to obtain the data from the first userequipment and the data from the second user equipment.

A method in a wireless communication system is further provided inanother aspect of the present disclosure, which includes: a transmittingstep of transmitting a first power signal portion to a base station at afirst transmission power on first radio transmission resources, whichare the same as radio transmission resources on which a second userequipment transmits a second power signal portion; a receiving step ofreceiving a retransmission request from the base station; and aprocessing step of processing, in response to the retransmissionrequest, the first power signal portion with a predetermined processingcoefficient to obtain a third power signal portion, wherein thetransmitting step further comprises transmitting the third power signalportion to the base station at a third transmission power on secondradio transmission resources, which are the same as radio transmissionresources on which the second user equipment transmits a fourth powersignal portion, the fourth power signal portion being obtained byprocessing, by the second user equipment, the second power signalportion with a predetermined processing coefficient in response to theretransmission request.

An electronic device is further provided in another aspect of thepresent disclosure, which includes a transceiver and one or moreprocessors. The one or more processors may be configured to execute themethods or functions of the units in the wireless communication systemaccording to the present disclosure described above.

Computer program codes and a computer program product for implementingthe methods of the present disclosure, and a computer readable storagemedium, on which the computer program codes for implementing the methodsof the present disclosure are recorded, are further provided in otheraspects of the present disclosure.

According to the embodiments of the present disclosure, by performingpredetermined processing for a retransmitted signal in multi-streamsuperposition to reduce interference caused by transmission with respectto other user equipment, it is possible to improve a data receptionsuccess rate and throughout of the multi-stream superpositiontransmission.

Other aspects of embodiments of the present disclosure are given in thefollowing parts of the description. In which, detailed illustration isused to sufficiently disclose preferred embodiments of the embodimentsof the present disclosure rather than to limit the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure can be better understood with reference to the detaileddescription given below in conjunction with the accompanying drawings,throughout which identical or like reference signs denote identical orlike components. The accompanying drawings together with the followingdetailed description are incorporated into and form a part of thespecification and serve to further illustrate the preferred embodimentsof the disclosure and to explain the principle and advantages of thedisclosure by way of example. In the drawings:

FIG. 1 is a block diagram showing a functional configuration example ofa device in a wireless communication system according to an embodimentof the present disclosure;

FIG. 2 is a block diagram showing a functional configuration example ofa device in a wireless communication system according to anotherembodiment of the present disclosure;

FIG. 3 is a flow diagram showing an example of a signaling interactionprocess for downlink transmission according to an embodiment of thepresent disclosure;

FIG. 4 is a block diagram showing a functional configuration example ofa device in a wireless communication system according to yet anotherembodiment of the present disclosure;

FIG. 5 is a block diagram showing a functional configuration example ofa device in a wireless communication system according to still anotherembodiment of the present disclosure;

FIG. 6 is a flow diagram showing an example of a signaling interactionprocess for uplink transmission according to an embodiment of thepresent disclosure;

FIG. 7 is a flow diagram showing a process example of a method in awireless communication system according to an embodiment of the presentdisclosure;

FIG. 8 is a flow diagram showing a process example of a method in awireless communication system according to another embodiment of thepresent disclosure;

FIG. 9 is a flow diagram showing a process example of a method in awireless communication system according to yet another embodiment of thepresent disclosure;

FIG. 10 is a flow diagram showing a process example of a method in awireless communication system according to still another embodiment ofthe present disclosure;

FIG. 11 is a block diagram showing an exemplary structure of a personalcomputer as an information processing device used in an embodiment ofthe present disclosure;

FIG. 12 is a block diagram illustrating a first example of a schematicconfiguration of an evolved Node B (eNB) to which the technology of thepresent disclosure may be applied;

FIG. 13 is a block diagram illustrating a second example of a schematicconfiguration of an eNB to which the technology of the presentdisclosure may be applied; and

FIG. 14 is a block diagram illustrating an example of a schematicconfiguration of a smartphone to which the technology of the presentdisclosure may be applied.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Exemplary embodiments of the present disclosure will be described belowin conjunction with the accompanying drawings. For the sake of clarityand conciseness, not all the features of practical implementations aredescribed in the specification. However, it is to be appreciated thatnumerous implementation-specific decisions shall be made duringdeveloping any of such practical implementations so as to achieve thedeveloper's specific goals, for example, to comply with system- andbusiness-related constraining conditions which will vary from oneimplementation to another. Moreover, it shall also be appreciated thatsuch a development effort might be very complex and time-consuming butmay simply be a routine task for those skilled in the art benefitingfrom this disclosure.

It shall further be noted that only those device structures and/orprocess steps closely relevant to the solutions of the disclosure areillustrated in the drawings while other details less relevant to thedisclosure are omitted so as not to obscure the disclosure due to thoseunnecessary details.

The embodiments of the present disclosure will be described in detailwith reference to FIG. 1 to FIG. 14 below.

Before specifically describing the embodiments of the presentdisclosure, superposition coding will be briefly introduced.

By means of the superposition coding, a transmitter can communicate withmultiple receivers on same transmission resources. For example, in theexisting downlink multi-user superposition transmission, a base stationcan simultaneously transmit multiple data streams to one or more useequipment, without making distinction using different time, frequenciesor multi-antenna technology. As an example, it is considered a radiotransmitter Tx communicates with a first receiver Rx1 via a firstphysical communication link L1, and communicates with a first receiverRx2 via a second communication link L2. Assuming a radio condition ofthe first receiver/link (for example, the first receiver is far awayfrom the transmitter) is poor, and a radio condition of the secondreceiver/link (for example, the second receiver is close to thetransmitter) is strong, which scenario may be temporary since the radiocondition is constantly changing especially for a mobile station. Inother words, in a case of a fixed transmission radio power, a Signal toInterference plus Noise Ratio (SINR) and a carrier to interference ratio(C/I) of the first receiver are lower (or much lower) than those of thesecond receiver. The transmitter Tx having known the radio conditions ofthe two receivers may proportionally allocate power budget between thetwo receivers for a particular time slot and a particular carrierfrequency, so that a first data block specific to the first receiver Rx1(the receiver in a poor radio condition) is transmitted at a higherpower as compared with a second data block specific to the secondreceiver Rx2 (the receiver in a strong radio condition). For example, ina case that the current radio condition and extra interference caused bytransmission of the second data block to the second receiver Rx2 aregiven, the transmitter Tx may apply sufficient power for the first datablock specific to the first receiver Rx1, to allow the first receiverRx1 to decode the data block. The transmitter Tx may then apply a power,which is smaller, but is still enough for the second receiver Rx2 todecode the second data block by using interference cancellation foreliminating or reducing interference caused by transmission of the firstdata block, for the second data block specific to the second receiverRx2. The transmitter Tx then transmits the two data blocks on a samecarrier frequency at the same time. Therefore, the two data blocks maybe regarded as “colliding” with each other. Since the first data blockis transmitted at a higher allocated power higher than the second datablock, the second data block is presented as a noise or interferenceincrement with respect to the first receiver Rx1. If a differencebetween the transmission powers of the two data blocks is high enough,SINR degradation at the first receiver Rx1 may be relatively small oreven ignored. Therefore, if the first data block is transmitted atsufficient power in consideration of a transmission rate of the firstdata block, a current radio condition and extra interference caused bytransmission of the second data block, the first receiver Rx1 can obtainthe first data block through decoding. The second receiver Rx2 can alsoobtain the first data block through decoding, since the second receiverRx2 receives the first data block under a SINR better than the SINR ofthe first receiver Rx1 due to the strong radio condition of the secondreceiver Rx2. Once the second receiver Rx2 obtains the first data blockthrough decoding, the second receiver Rx2 regards the first data blockas interference and eliminates the interference from a total signalreceived during a time period in which the two data blocks are receivedusing a known interference cancellation technology. A remaining signalrepresents the second data block combined with a noise and interferencefrom other sources. If the second data block is transmitted atsufficient power (which is lower than the power for the first datablock) in consideration of a transmission rate of the second data blockand the radio condition of the second receiver Rx2, the second receiverRx2 can obtain the second data block through decoding.

It should be noted that the method may be extended to be applied tothree or more receivers. For example, a highest power may be allocatedto a receiver in the poorest radio condition for transmission, a lowestpower may be allocated to a receiver in the strongest radio conditionfor transmission, and a middle power may be allocated to a receiver in amiddle radio condition. The receiver in the strongest radio conditionmay obtain a data block specific to the receiver in the poorest radiocondition through decoding and eliminates the decoded data block fromthe received signal, then obtains a data block specific to the receiverin the middle radio condition through decoding and eliminates the seconddecoded block, and finally obtains a data block specific to the receiveritself through decoding (the decoding/eliminating process may bereferred to as successive interference cancellation). The receiver inthe middle radio condition may obtain a data block specific to thereceiver in the poorest radio condition through decoding and eliminatesthe decoded data block from the received signal, and then obtains a datablock specific to the receiver itself through decoding. The receiver inthe poorest radio condition may directly decode a data block specific tothe receiver itself, since the data block is transmitted at the highestpower. It should be understood that those skilled in the art can extendthe successive interference cancellation technology to be applied tofour or more receivers without extra experiments or further creativelabor. The receiver may be a mobile station, for example a userequipment, and the transmitter may be a base transceiver station, forexample an eNB, the data block may be for example a data package, atransport block.

With the development of the superposition coding technology, theinventor of the present disclosure recognizes retransmission issues suchas hybrid automatic repeat request (HARQ) or the like when applying thesuperposition coding technology into an actual communication system. Ifa data block cannot be obtained through decoding at any receiver in theabove process, the receiver may transmit a retransmission request to thetransmitter. However, if the superposed data block (which cannot beobtained through decoding in the first transmission) is simplyretransmitted as in the above superposition coding technology, since theinterference caused by transmission of the data blocks for otherreceiver is also enhanced in the retransmission, the receiver stillcannot obtain the data block through decoding (even if e.g. tracking andmerging is performed with the data block transmitted previously), evenif the transmitter retransmits the signal. The technology in the presentdisclosure aims to address the signal retransmission in thesuperposition coding transmission, and the embodiments of the presentdisclosure are described in detail below.

It should be understood that the superposition coding technology isbriefly introduced above by taking the downlink transmission as anexample, however, in uplink transmission, that is, when multipletransmitters simultaneously transmit to a single receiver on the samefrequency, a similar process as above may be executed at the singlereceiver. In this case, the receiver may be a base transceiver station,for example an eNB, and the multiple transmitters may be mobilestations, for example user equipment.

FIG. 1 is a block diagram showing a functional configuration example ofa device in a wireless communication system according to an embodimentof the present disclosure. The device may be for example included in thebase station or on a base station side.

As shown in FIG. 1, a device 100 according to the embodiment may includea transmitting unit 102, a receiving unit 104 and a processing unit 106.Functional configuration examples of the above units are described indetail below.

The transmitting unit 102 may be configured to transmit a firstallocation signal superposed using superposition coding to multiple userequipment including at least a first user equipment and a second userequipment. The first allocation signal may include at least a firstpower signal portion for the first user equipment and a second powersignal portion for the second user equipment.

It should be noted that, for facilitating illustration, a case that abase station transmits a signal superposed using superposition coding totwo user equipment including the first user equipment and the seconduser equipment is taken as an example, however, it should be understoodthat the base station may simultaneously transmit a signal superposedusing superposition coding to three or more user equipment, and thetechnology in the present disclosure can also be applied thereto. Thefirst power signal portion refers to a signal portion carrying a targetdata block for the first user equipment transmitted to the first userequipment at for example a first power, and the second power signalportion refers to a signal portion carrying a target data block for thesecond user equipment transmitted to the second user equipment at forexample a second power. It can be known according to the abovesuperposition coding technology that the first power may be greater orless than the second power according to the radio conditions of thefirst user equipment and the second user equipment.

The receiving unit 104 may be configured to receive a retransmissionrequest fed back from at least one of the first user equipment and thesecond user equipment. In a case that at least one of the first userequipment and the second user equipment fails to decode datacorresponding thereto based on the first allocation signal, the at leastone of the first user equipment and the second user equipment maytransmit a retransmission request to the base station to request signalretransmission.

The processing unit 106 may be configured to process, in response to theretransmission request, the first power signal portion and the secondpower signal portion with predetermined processing coefficients toobtain a second allocation signal.

Then, the transmitting unit 102 may be further configured to transmitthe second allocation signal to the first user equipment and the seconduser equipment, so that the first user equipment and the second userequipment merge the first allocation signal and the second allocationsignal to obtain data for the first user equipment and data for thesecond user equipment.

It should be understood that although it is described here the basestation simultaneously transmits a retransmitted signal to both thefirst user equipment and the second user equipment in theretransmission, the present disclosure also intends to give an examplethat the base station transmits a signal to only the user equipmentwhich transmits the retransmission request. However, for the convenienceof description, a case that the base station transmits the retransmittedsignal to all user equipment upon receiving the retransmission requestis taken as an example for description, and a case that the base stationtransmits a signal to only the user equipment which transmits theretransmission request is regarded as a special case that a power signalportion for the user equipment which does not transmit theretransmission request is set to 0 in the retransmitted signal, whichwill not be separately described here.

Actually, data decoding of different user equipment is associated withone another in the multi-user superposition transmission, thus if datadecoding of one user equipment is failed in the first transmission, itis likely that other user equipment also fail to decode the data andtransmit a retransmission request. Compared with respectively performingretransmission to the first user equipment and the second user equipmenton different transmission resources as in a general approach, in anexample of the present disclosure, when performing the retransmission,specific processing is performed and the superposition coding is stilladopted to simultaneously perform retransmission to the first userequipment and the second user equipment on the same transmissionresources, thereby significantly improving utilization efficiency of theresources and ensuring a success rate of retransmission to some extent.Such performance gain is more apparent in a case that more userequipment participate in superposition transmission.

Preferably, in order to reduce interference caused by transmission withrespect to other user equipment, in the merged first allocation signaland second allocation signal, one of the first power signal portion andthe second power signal portion is weakened or eliminated.

In order to weaken or eliminate interference in the merged signal, thedevice 100 adjusts, before performing retransmission using thesuperposition coding, an interaction relation between the signal portionfor the first user equipment and the signal portion for the second userequipment on the same transmission resources. For example, if the signalportion for the first user equipment and the signal portion for thesecond user equipment are added to be transmitted on the sametransmission resources in a previous transmission, the device 100performs subtraction between the signal portion for the first userequipment and the signal portion for the second user equipment and thentransmits the signal after subtraction on the same retransmissionresources in retransmission. In this case, at the receiving userequipment end, the signal portion for other user equipment asinterference may be weakened simply by merging the received signals inthe two transmissions. In other words, one of the first power signalportion and the second power signal portion is multiplied by aprocessing coefficient of −1 in the retransmission, and the other of thefirst power signal portion and the second power signal portion remainsunchanged or is multiplied by a processing coefficient of 1. Preferably,the predetermined processing coefficients may be determined based on aHadamard matrix. As an example, the predetermined processingcoefficients may be referred to as “a layer-time code matrix”hereinafter, a horizontal dimension of the matrix represents a maximumretransmission count, and a vertical dimension of the matrix representsthe number of data streams (corresponding to the number of the userequipment). The layer-time code matrix may be represented as forexample:

In the described example, assuming a base station transmits two datablocks b_(F) and b_(N) to the first user equipment and the second userequipment respectively, and modulated symbol strings corresponding tothe two data blocks may be represented as d_(F) and d_(N). Assuming thefirst user equipment is in a poor radio channel (for example, far awayfrom the base station), and the second user equipment is in a strongradio channel (for example, close to the base station). A layer-timecode matrix used by the base station is a Hadamard matrix A of 2×(R+1)(where R+1 represents a maximum transmission count), which can beobtained by repeating a Walsh matrix of 2×2.

${\quad A} = \begin{pmatrix}1 & 1 & \cdots & 1 & 1 \\1 & {- 1} & \cdots & 1 & {- 1}\end{pmatrix}$

where a first row of the matrix includes predetermined coefficients forthe first user equipment in respective times of retransmissions, and asecond row of the matrix includes predetermined coefficients for thesecond user equipment in respective times of retransmissions. Assuming adownlink channel between the base station and the first user equipmentand a downlink channel between the base station and the second userequipment are respectively represented as h_(F,0) and h_(N,0) in a firsttransmission. The base station allocates a transmission power p_(F,0)and a transmission power p_(N,0) for data block transmission to the twouser equipment based on attenuation conditions of h_(F,0) and h_(N,0),p_(F,0)>p_(N,0). In the first transmission, the retransmission count is0, and the base station respectively weights d_(F) and d_(N) withcoefficients A(0,0)=1 and A(1,0)=1 in a zero column in the layer-timecode matrix, and superposes the weighted results to obtain a basebandsignal string x₀ to be transmitted (that is, the above first allocationsignal).

where x₀=√{square root over (p_(F,0))}A(0,0)d_(F)+√{square root over(p_(N,0))}A(1,0)d_(N)=√{square root over (p_(F,0))}d_(F)+√{square rootover (p_(N,0))}d_(N)(√{square root over (p_(F,0))}d_(F) is the firstpower signal portion, and √{square root over (p_(N,0))}d_(N) is thesecond power signal portion).

A signal received by the first user equipment in the first transmissionmay be represented as:

y _(F,0) =h _(F,0)(√{square root over (p _(F,0))}d _(F)+√{square rootover (p _(N,0))}d _(N))+n _(F,0)

where n_(F,0) is additive noise received by the first user equipment inthe first transmission.

A signal received by the second user equipment in the first transmissionmay be represented as:

y _(N,0) =h _(N,0)(√{square root over (p _(F,0))}d _(F)+√{square rootover (p _(N,0))}d _(N))+n _(N,0)

where n_(N,0) is additive noise received by the second user equipment inthe first transmission.

The first user equipment regards the second power signal portion√{square root over (p_(N,0))}d_(N) as a part of the noise upon receivingx₀, and performs demodulation and self-checking (for example, usingcyclic redundant check, CRC) for y_(F,0) based on h_(F,0) and p_(F,0).The second user equipment performs demodulation and self-checking fory_(N,0) based on h_(n,0) and p_(F,0) upon receiving x₀ to obtain b_(F),recoveries an interference signal h_(N,0)√{square root over(p_(F,0))}d_(F) based on b_(F), and then eliminates the interferencesignal h_(N,0)√{square root over (p_(F,0))}d_(F) from y_(N,0), andperforms demodulation and self-checking using y_(N,0)−h_(N,0)√{squareroot over (p_(F,0))}d_(F) based on h_(N,0) and p_(N,0).

If the first user equipment and the second user equipment determine thatthe data blocks are correctly received by self-checking, the first userequipment and the second user equipment inform the base station totransmit next data blocks, for example, the first user equipment and thesecond user equipment transmit acknowledgement (ACK) information of 1bit to the base station via the uplink channels thereof. The basestation waits for the acknowledgement information for the transmitteddata blocks from the user equipment after transmitting the data blocks,and transmits next data blocks upon receiving the acknowledgementinformation.

However, if one of the first user equipment and the second userequipment determines that the data block is not correctly received byself-checking, the user equipment may inform the base station toretransmit the data block. For example, the first user equipment and/orthe second user equipment transmit negative acknowledgement (NACK)information of 1 bit to the base station via the uplink channels thereofas a retransmission request. Upon receiving the retransmission request,optionally, the base station reallocates transmission powers p_(F,1) andp_(N,1) to data blocks of the two user equipment based on attenuationconditions of the downlink channels h_(F,1) and h_(N,1) (in order toreduce system overhead or simplify calculation complexity, the basestation may re-use the transmission powers allocated for the previoustransmission, that is, p_(F,1)=p_(F,0), p_(N,1)=p_(N,0)),p_(F,1)>p_(N,1). The retransmitted d_(F) and d_(N) are weighted withpredetermined processing coefficients (that is, coefficients A(0,1)=1and A(1,1)=−1 in a first column in the layer-time code matrix), and theweighted results are superposed to obtain a baseband signal string x₁ tobe transmitted (that is, the second allocation signal above), where

x ₁=√{square root over (p _(F,1))}A(0,1)d _(F)+√{square root over (p_(N,1))}A(1,1)d _(N)=√{square root over (p _(F,1))}d _(F)−√{square rootover (p _(N,1))}d _(N)

It should be understood that in the above example, the device 100 mayfor example generate a complete layer-time code matrix in advance, inwhich, each of the rows corresponds to each of data streams of all userequipment, and each of the columns corresponds to each of theretransmission counts. For a retransmission count, predeterminedcoefficients in a corresponding column are acquired to convenientlyprocess the data streams of the user equipment. In an optional example,the device 100 may generate a coefficient based on a currentretransmission count and user equipment involved in the retransmissionin a real-time manner for processing.

A signal received by the first user equipment in a first retransmission(a second transmission) may be represented as:

y _(F,1) =h _(F,1)(√{square root over (p _(F,1))}d _(F)−√{square rootover (p _(N,1))}d _(N))+n _(N,1)

where h_(F,1) denotes a channel of the first user equipment in the firstretransmission, and n_(F,1) denotes additive noise for the first userequipment in the first retransmission.

A signal received by the second user equipment in the firstretransmission may be represented as:

y _(N,1) =h _(N,1)(√{square root over (p _(F,1))}d _(F)−√{square rootover (p _(N,1))}d _(N))+n _(N,1)

where h_(N,1) denotes a channel of the second user equipment in thefirst retransmission, and n_(N,1) denotes additive noise for the seconduser equipment in the first retransmission.

In a schematic simplified example, a time interval between theretransmission and the previous transmission is very small, changes inthe channel between the base station and the first user equipment andthe channel between the base station and the second user equipment maybe ignored, and transmission powers used in the two transmissions remainunchanged (that is, h_(F,1)=h_(F,0), h_(N,1)=h_(N,0), p_(F,1)=p_(F,0),p_(N,1)=p_(N,0)). The first user equipment performs positive mergingbased on y_(F,0) and y_(F,1) received respectively in the two downlinkdata transmissions, and a signal obtained by the positive merging isrepresented as:

y _(F) =y _(F,0) +y _(F,1)

In the merged signal, the signal portion for the second user equipmentis eliminated, and the signal portion for the first user equipment isenhanced, therefore, the first user equipment can obtain its target datablock through decoding.

On the other hand, the second user equipment performs negative mergingbased on y_(N,0) and y_(N,1) received respectively in the two downlinkdata transmissions, and a signal obtained by the negative merging isrepresented as:

y _(N) =y _(N,0) −y _(N,1)

In the merged signal, the signal portion for the first user equipment iseliminated, and the signal portion for the second user equipment isenhanced, therefore, the second user equipment can obtain its targetdata block through decoding.

As an optional embodiment, in a case that the channel conditions andtransmission powers change significantly in the two transmissions, thefirst user equipment performs positive merging based on y_(F,0) andy_(F,1) received respectively in the two downlink data transmissions asfollows, and a signal obtained by the positive merging is representedas:

$\begin{matrix}{y_{F} = {{\sqrt{p_{F,1}}{h_{F,1}}^{2}h_{F,0}^{*}y_{F,0}} + {\sqrt{p_{F,0}}{h_{F,0}}^{2}h_{F,1}^{*}y_{F,1}}}} \\{= {{2\sqrt{p_{F,0}p_{F,1}}{h_{F,0}}^{2}{h_{F,1}}^{2}d_{F}} + {{h_{F,0}}^{2}{h_{F,1}}^{2}}}} \\{{{( {\sqrt{p_{F,1}p_{N,0}} - \sqrt{p_{F,0}p_{N,1}}} )d_{N}} + {\sqrt{p_{F,1}}{h_{F,1}}^{2}h_{F,0}^{*}n_{F,0}} +}} \\{{\sqrt{p_{F,0}}{h_{F,0}}^{2}h_{F,1}^{*}n_{F,1}}}\end{matrix}\quad$

It can be seen from y_(F) that the positive merging is performed withy_(F,0) and y_(F,1) being multiplied by particular parametersrespectively, and the particular parameters are used to enhance d_(F)and weaken d_(N) using mathematical approaches in a case that thechannel conditions and the powers are changed. It should be understoodthat those skilled in the art may also design other particularparameters according to the ideas of the present disclosure topreprocess y_(F,0) and y_(F,1) before merging for realizing the samepurpose, for example, removing a part related to the power in the aboveequation, which will not be enumerated here in the present disclosure.Then, the first user equipment performs demodulation and self-checkingfor y_(F) to obtain the target data stream b_(F).

On the other hand, similarly, the second user equipment performsnegative merging based on y_(N,0) and y_(N,1) and a signal obtained bythe negative merging is represented as:

$\begin{matrix}{y_{N}^{\prime} = {{\sqrt{p_{N,1}}{h_{N,1}}^{2}h_{N,0}^{*}y_{N,0}} - {\sqrt{p_{N,0}}{h_{N,0}}^{2}h_{N,1}^{*}y_{N,1}}}} \\{= {{2\sqrt{p_{N,0}p_{N,1}}{h_{N,0}}^{2}{h_{N,1}}^{2}d_{N}} + {{h_{N,0}}^{2}{h_{N,1}}^{2}}}} \\{{{( {\sqrt{p_{N,1}p_{F,0}} - \sqrt{p_{N,0}p_{F,1}}} )d_{F}} + {\sqrt{p_{N,1}}{h_{N,1}}^{2}h_{N,0}^{*}n_{N,0}} +}} \\{{\sqrt{p_{N,0}}{h_{N,0}}^{2}h_{N,1}^{*}n_{N,1}}}\end{matrix}\quad$

It can be seen from y_(N) that d_(N) is enhanced while interferencepower d_(F) is weakened. The second user equipment performs demodulationand self-checking for y_(N) to try to obtain the target data streamb_(N).

If the second user equipment cannot obtain the target data stream b_(N),the positive merging may be performed based on y_(N,0) and y_(N,1), anda signal obtained by the positive merging is represented as:

${\quad\begin{matrix}{y_{N}^{''} = {{\sqrt{p_{F,1}}{h_{N,1}}^{2}h_{N,0}^{*}y_{N,0}} - {\sqrt{p_{F,0}}{h_{N,0}}^{2}h_{N,1}^{*}y_{N,1}}}} \\{= {{2\sqrt{p_{F,0}p_{F,1}}{h_{N,0}}^{2}{h_{N,1}}^{2}d_{F}} + {{h_{N,0}}^{2}{h_{N,1}}^{2}}}} \\{{{( {\sqrt{p_{F,1}p_{N,0}} - \sqrt{p_{F,0}p_{N,1}}} )d_{N}} + {\sqrt{p_{F,1}}{h_{N,1}}^{2}h_{N,0}^{*}n_{N,0}} +}} \\{{\sqrt{p_{F,0}}{h_{N,0}}^{2}h_{N,1}^{*}n_{N,1}}}\end{matrix}}\quad$

It can be seen from y_(N)″ that d_(F) is enhanced while interferencepower of d_(N) is weakened. The second user equipment performsdemodulation and self-checking for y_(N)″ to obtain b_(F), removes aninterference signal |h_(N,0)|²|h_(N,1)|²(√{square root over(p_(N,1)p_(F,0))}−√{square root over (p_(N,0)p_(F,1))})d_(F) fromy_(N)′, and performs demodulation and self-checking for d_(N) to obtainb_(N). Optionally, the second user equipment may also firstly performpositive merging to obtain y_(N)″ and obtain b_(N) through decoding withthe above method, and in a case of failing to obtain b_(N) throughdecoding, the second user equipment then performs negative merging toobtain y_(N)′ and obtains b_(N) through decoding.

As another embodiment, the base station informs not only the allocatedpower for d_(F) but also the allocated power for a signal portion d_(N)of the second user equipment to the first user equipment. The first userequipment performs merging based on y_(F,0) and y_(F,1) for eliminatinginterference d_(N) and enhancing d_(F).

$\begin{matrix}{y_{F} = {{\sqrt{p_{N,1}}{h_{F,1}}^{2}h_{F,0}^{*}y_{F,0}} + {\sqrt{p_{N,0}}{h_{F,0}}^{2}h_{F,1}^{*}y_{F,1}}}} \\{= {{( {\sqrt{p_{N,1}p_{F,0}} + \sqrt{p_{N,0}p_{F,1}}} ){h_{F,0}}^{2}{h_{F,1}}^{2}d_{F}} +}} \\{{{\sqrt{p_{N,1}}{h_{F,1}}^{2}h_{F,0}^{*}n_{F,0}} + {\sqrt{p_{N,0}}{h_{F,0}}^{2}h_{F,1}^{*}n_{F,1}}}}\end{matrix}\quad$

It can be seen from y_(F) that d_(F) is enhanced while interferenced_(N) is eliminated. The first user equipment then performs demodulationand self-checking for y_(F) to obtain the target data stream b_(F).

Similarly, the second user equipment performs negative merging based ony_(N,0) and y_(N,1) for eliminating interference d_(F) and enhancingd_(N):

$\begin{matrix}{y_{N}^{\prime} = {{\sqrt{p_{F,1}}{h_{N,1}}^{2}h_{N,0}^{*}y_{N,0}} - {\sqrt{p_{F,0}}{h_{N,0}}^{2}h_{N,1}^{*}y_{N,1}}}} \\{= {{( {\sqrt{p_{F,1}p_{N,0}} - \sqrt{p_{F,0}p_{N,1}}} ){h_{N,0}}^{2}{h_{N,1}}^{2}d_{N}} +}} \\{{{\sqrt{p_{F,1}}{h_{N,1}}^{2}h_{N,0}^{*}n_{N,0}} + {\sqrt{p_{F,0}}{h_{N,0}}^{2}h_{N,1}^{*}n_{N,1}}}}\end{matrix}\quad$

It can be seen from y_(N)′ that d_(N) is enhanced while interferencepower of d_(F) is eliminated. The second user equipment performsdemodulation and self-checking for y_(N)′, to try to obtain the targetdata stream b_(N).

If the second user equipment fails to obtain the target data streamb_(N), the second user equipment performs positive merging based ony_(N,0) and y_(N,1) for eliminating interference d_(N) and enhancingd_(F), and a signal obtained through the positive merging is representedas:

$\begin{matrix}{y_{N}^{''} = {{\sqrt{p_{N,1}}{h_{N,1}}^{2}h_{N,0}^{*}y_{N,0}} - {\sqrt{p_{N,0}}{h_{N,0}}^{2}h_{N,1}^{*}y_{N,1}}}} \\{= {{( {\sqrt{p_{N,1}p_{F,0}} + \sqrt{p_{N,0}p_{F,1}}} ){h_{N,0}}^{2}{h_{N,1}}^{2}d_{F}} +}} \\{{{\sqrt{p_{N,1}}{h_{N,1}}^{2}h_{N,0}^{*}n_{N,0}} + {\sqrt{p_{N,0}}{h_{N,0}}^{2}h_{N,1}^{*}n_{N,1}}}}\end{matrix}\quad$

It can be seen from y_(N)″ that d_(F) is enhanced while interferenced_(N) is eliminated. The second user equipment then performs negativemerging based on y_(N,0) and y_(N,1), and a signal obtained through thenegative merging is represented as:

$\begin{matrix}{y_{N}^{\prime\prime\prime} = {{\sqrt{p_{N,1}}{h_{N,1}}^{2}h_{N,0}^{*}y_{N,0}} - {\sqrt{p_{N,0}}{h_{N,0}}^{2}h_{N,1}^{*}y_{N,1}}}} \\{= {{2\sqrt{p_{N,0}p_{N,1}}{h_{N,0}}^{2}{h_{N,1}}^{2}d_{N}} + {{h_{N,0}}^{2}{h_{N,1}}^{2}}}} \\{{{( {\sqrt{p_{N,1}p_{F,0}} - \sqrt{p_{N,0}p_{F,1}}} )d_{F}} + {\sqrt{p_{N,1}}{h_{N,1}}^{2}h_{N,0}^{*}n_{N,0}}}} \\{{\sqrt{p_{N,0}}{h_{N,0}}^{2}h_{N,1}^{*}n_{N,1}}}\end{matrix}\quad$

The second user equipment then performs demodulation and self-checkingfor y_(N)″ to obtain b_(F), and removes an interference signal|h_(N,0)|²|h_(N,1)|²(√{square root over (p_(N,1)p_(F,0))}−√{square rootover (p_(N,0)p_(F,1))})d_(F) from y_(N)″, and obtains performsdemodulation and self-checking for d_(N).

In demodulating the data signal, in an example, the transmission powersp_(F) and p_(N) are known to the first user equipment and the seconduser equipment, for example, the base station indicates the transmissionpowers p_(F) and p_(N) to the first user equipment and the second userequipment through control signaling. In this case, the user equipmentmay estimate channels h_(F) and h_(N) based on for example acell-specific reference signal (CRS) or a channel statusindicator-reference signal (CSI-RS), thereby obtaining the data b_(F)and b_(N) through decoding.

On the other hand, after the first transmission, if the first userequipment fails to correctly receive data while the second userequipment correctly receives data, as an embodiment, the base stationonly transmits a data block for the first user equipment with apredetermined coefficient (for example, p_(N,1) is set to be 0) for thenext time. The first user equipment may perform, in a case thatattempting to obtain the data through separately demodulating theretransmitted signal fails, positive merging for the signals received inthe two transmissions based on a corresponding layer-time code [A(0,0),A(0,1)]. Since the signal portion for the first user equipment isenhanced in the merged signal, a possibility that the first userequipment obtains its data through decoding is improved greatly. As amatter of course, in this case, the base station may also simultaneouslytransmit a data block for the first user equipment and a data block forthe second user equipment as described above, and an interfering signalportion is eliminated in the merging manner described above.

On the other hand, after the first transmission, if the second userequipment fails to correctly receive the data while the first userequipment correctly receives the data, as an embodiment, the basestation may only transmit a data block for the second user equipmentwith a predetermined coefficient for the next time. The second userequipment may perform, in a case that attempting to obtain the datathrough separately demodulating the retransmitted signal fails, negativemerging for the signals received in the two transmissions based on acorresponding layer-time code [A(1,0), A(1,1)]. Since the signal portionfor the second user equipment is enhanced in the merged signal, apossibility that the second user equipment obtains its data throughdecoding is improved greatly. As a matter of course, in this case, thebase station may also simultaneously transmit a data block for the firstuser equipment and a data block for the second user equipment asdescribed above, and an interfering signal portion is eliminated in themerging manner described above. In other words, in a case that only oneof the first user equipment and the second user equipment fails tocorrectly receive the data block, the base station may alsosimultaneously transmit the data block for the first user equipment andthe data block for the second user equipment in the manner describedabove, and the interfering signal portion is eliminated in the mergingmanner described above.

It should be noted in a case that the data block for the user equipmentwhich fails to obtain the data through demodulating is transmittedseparately in the retransmission, the user equipment may adopt multiplemerging decoding schemes in addition to the above examples. For example,in the previous paragraph, the second user equipment may also performpositive merging for the signals received in the two transmissions toeliminate d_(N), and derives target data d_(N) after obtaining d_(F)through decoding. Alternatively, the decoding schemes may be combined ina specific order and then are executed successively, which are notenumerated here for conciseness.

The above retransmission process may be repeated until a maximumretransmission count of user data is reached. If the data demodulationstill fails in this case, unsuccessful transmission is announced and thetransmission is abandoned. The data retransmission count may be limitedin for example high layer configuration of the base station, and isindicated to the user equipment through signaling. For example, amaximum retransmission count maxHARQ-Tx configured through radioresource control (RRC) may be applied in the present disclosure.

It should be noted that although a matrix element of the layer-time codematrix determined based on a Hadamard matrix is 1 or −1 in the abovedescribed example, the matrix element may be other elements than 1 or−1, as long as one of the first power signal portion and the secondpower signal portion is weakened or eliminated in the merged signal.

In addition, it should also be noted that although positive additivemerging or negative subtractive merging is performed at the first userequipment and the second user equipment respectively in the abovedescribed example, the positive additive merging or the negativesubtractive merging is performed at both the first user equipment andthe second user equipment, thus data corresponding to one of the firstpower signal portion and the second power signal portion may be obtainedthrough decoding, and then data corresponding to the other power signalportion may be derived accordingly.

That is, the exemplary calculation process described above is merely anexample rather than limitation, and those skilled in the art may adjustthe above calculation process according to principles of the presentdisclosure, and such adjustment is considered to fall within the scopeof the present disclosure.

In addition, it should be understood that in addition to or instead ofprocessing the first power signal portion and the second power signalportion with predetermined processing coefficients, the processing unit106 may be further configured to adjust, in response to theretransmission request, a transmission power of at least one of thefirst power signal portion and the second power signal portion to obtaina second allocation signal.

Specifically, if the transmission power of the first power signalportion is greater than the transmission power of the second powersignal portion, in a case that data reception of at least one of thefirst user equipment and the second user equipment fails, the processingunit 106 may further increase the transmission power of the first powersignal portion and accordingly reduce the transmission power of thesecond power signal portion in the retransmission. Thus, the first userequipment and the second user equipment may firstly obtain datacorresponding to the first power signal portion through decoding basedon the merged first allocation signal and second allocation signal, andthen derive data corresponding to the second power signal portionthrough non-linear interference cancellation such as successiveinterference cancellation.

Preferably, in order to make the first user equipment and the seconduser equipment respectively perform corresponding merging (for example,an addition operation or a subtraction operation) for the firstallocation signal and the second allocation signal described above so asto eliminate interference to the greatest extent and reduce calculationload, the transmitting unit 102 may be further configured to transmitmerging indications indicating how to perform merging to the first userequipment and the second user equipment, so that the first userequipment and the second user equipment merge the first allocationsignal and the second allocation signal according to the mergingindications. Preferably, the transmitting unit 102 may notify the userequipment of the merging indications by including the mergingindications in high-layer signaling (for example, RRC signaling, MAClayer signaling or the like). The merging indication may include theabove layer-time code matrix and/or a row number corresponding to theuser equipment. In an example in which the predetermined processingcoefficients are generated at the base station side in a real-timemanner, the predetermined processing coefficients, the additive merging,the subtractive merging and the like with respect to the currenttransmission base station may be notified to the first user equipmentand the second user equipment through physical layer signaling (forexample, downlink control information DCI). If the merging indication iscontained in the physical layer signaling, the physical layer signalingmay be transmitted through physical downlink control channel (PDCCH),and time variation is better in this case.

The most possible application scenario of the multi-user superpositioncoding may be that only one far user equipment and one near userequipment share transmission resources. Therefore, in an optionalexample, knowledge about a layer-time code matrix is for example knownin advance on the base station side and the user equipment side. In thelayer-time code matrix, a first row fixedly corresponds toretransmission processing coefficients of the far user equipment, and asecond row fixedly corresponds to retransmission processing coefficientsof the near user equipment. In this example, the layer-time code matrixis stored in advance in a memory of the user equipment, and the userequipment may determine whether the user equipment itself is the faruser equipment or the near user equipment based on for exampletransmission powers for the two user equipment indicated by the basestation (power of the far user equipment is large, and power of the nearuser equipment is small), and further reads predetermined coefficientsin the layer-time code matrix for the merging operation.

Preferably, the merging indication may be to perform merging to enhancea higher one of the first power signal portion and the second powersignal portion. As described above, for the first power signal portion√{square root over (p_(F,0))}d_(F) and the second power signal portion√{square root over (p_(N,0))}d_(N), if the first power signal portion isgreater than the second power signal portion, the merging indication maybe to perform additive merging for the first allocation signal √{squareroot over (p_(F,0))}d_(F)+√{square root over (p_(N,0))}d_(N), and thesecond allocation signal √{square root over (p_(F,1))}d_(F)−√{squareroot over (p_(N,1))}d_(N) at both the first user equipment and thesecond user equipment to enhance the first power signal portion, so thatdata corresponding to the first power signal portion is obtained firstthrough decoding at both the first user equipment and the second userequipment, and data corresponding to the second power signal portion isderived through for example successive interference cancellation.Otherwise, if the first power signal portion is less than the secondpower signal portion, the merging indication may be to performsubtractive merging for the first allocation signal √{square root over(p_(F,0))}d_(F)+√{square root over (p_(N,0))}d_(N) and the secondallocation signal √{square root over (p_(F,1))}d_(F)−√{square root over(p_(N,1))}d_(N) at both the first user equipment and the second userequipment to enhance the second power signal portion, so that datacorresponding to the second power signal portion is obtained firstthrough decoding at both the first user equipment and the second userequipment, and data corresponding to the first power signal portion isderived through for example successive interference cancellation.

In addition, preferably, the merging indication may be to performmerging to respectively enhance the first power signal portion for thefirst user equipment and the second power signal portion for the seconduser equipment. That is, the base station may indicate the first userequipment and the second user equipment to perform merging to enhance apower signal portion corresponding to its own target data block.

It should be understood that the merging indication may be optional.That is, the base station may not transmit the merging indication to theuser equipment, and the user equipment may perform default merging (forexample, additive merging) based on a normal case. If data cannot beobtained through decoding based on the default merging the subtractivemerging may be performed. In other words, the user equipment may alsodetermine how to perform merging itself, thereby reducing signalingoverhead.

It can be understood that although an exemplary processing in which theretransmitted signal is processed to weaken or eliminate the first powersignal portion or the second power signal portion in the mergedfirst-transmitted signal and retransmitted signal is given above, theexemplary processing is merely an example rather than limitation, andthose skilled in the art may modify the above process according to theprinciples of the present disclosure.

A functional configuration example of a device on a base station side isdescribed above with reference to FIG. 1. Next, a functionalconfiguration example of a device on a user equipment side in a wirelesscommunication system according to another embodiment of the presentdisclosure is described with reference to FIG. 2. FIG. 2 is a blockdiagram showing a functional configuration example of a device on a userequipment side in a wireless communication system according to anotherembodiment of the present disclosure. The device may be located in theuser equipment or on a user equipment side.

As shown in FIG. 2, a device 200 according to the embodiment may includea receiving unit 202, a processing unit 204 and a transmitting unit 206.Functional configuration examples of the units are described in detailbelow.

The receiving unit 202 may be configured to receive a first allocationsignal from a base station. The first allocation signal is superposedthrough superposition coding, and includes at least a first power signalportion for a first user equipment and a second power signal portion fora second user equipment.

The processing unit 204 may be configured to obtain data for the firstuser equipment based on the first allocation signal. For example, theprocessing unit 204 may obtain data for the first user equipment basedon the first allocation signal through interference cancellation,demodulation and self-checking and the like.

Due to the existence of interference and the like, the processing unit204 may not correctly obtain data through decoding based on the firstallocation signal. In this case, the transmitting unit 206 may beconfigured to transmit, in a case that the processing unit 204 fails toobtain data for the first user equipment based on the first allocationsignal, a retransmission request to the base station, so that the basestation may transmit a second allocation signal to the first userequipment.

The receiving unit 202 may be further configured to receive the secondallocation signal from the base station. The second allocation signal isobtained by processing, by the base station, the first power signalportion and the second power signal portion with predeterminedprocessing coefficients in response to the retransmission request fedback from at least one of the first user equipment and the second userequipment. A specific process of obtaining the second allocation signalmay be referred to the foregoing description at corresponding positions,and is not repeated here anymore.

The processing unit 204 may be further configured to merge the firstallocation signal and the second allocation signal to weaken oreliminate one of the first power signal portion and the second powersignal portion in the merged signal, thereby obtaining data for thefirst user equipment.

As described above, the processing unit 204 may perform merging toweaken or eliminate the second power signal portion so as to directlyobtain data corresponding to the first power signal portion throughdecoding. Alternatively, the processing unit 204 may perform merging tofirst obtain the higher power signal portion (for example, the secondpower signal portion) through decoding, and then indirectly obtain datacorresponding to the first power signal portion through non-linearinterference cancellation for example successive interferencecancellation based on a result of the merging.

Preferably, the processing unit 204 may be further configured to mergethe first allocation signal and the second allocation signal to enhancea higher one of the first power signal portion and the second powersignal portion, obtain data corresponding to the higher power signalportion through decoding, and then derive data corresponding to a lowerpower signal portion through non-linear interference cancellation forexample successive interference cancellation.

Alternatively, as a preferred example, the processing unit 204 may befurther configured to merge the first allocation signal and the secondallocation signal to enhance the first power signal portion for thefirst user equipment. Similarly, the similar processing may also beexecuted at the second user equipment. That is, the processing unit 204of the user equipment may determine how to perform merging to enhance apower signal portion corresponding to a target data block of the userequipment, so as to directly obtain the desired target data.

Preferably, in order that each user equipment can perform merging toobtain its own data through decoding, the receiving unit 206 may furtherreceive a merging indication from the base station, so that theprocessing unit 204 may further perform merging (for example, additivemerging or subtractive merging) on the first allocation signal and thesecond allocation based on the merging indication. The mergingindication may be for example contained in high-layer signaling (forexample, RRC signaling, MAC layer signaling and the like) or aphysical-layer signaling (for example, DCI). Preferably, as describedabove, the merging indication may be not necessarily different forrespective user equipment, and the merging indication may also be toperform merging to enhance a higher one of the first power signalportion and the second power signal portion or to enhance a power signalportion corresponding to a target data block of respective userequipment.

When decoding a data signal, in a case that a transmission power isknown by the user equipment, the processing unit 204 may be furtherconfigured to estimate a channel status (h0 described above) based onCRS or CSI-RS from the base station, and obtain data through decodingbased on the transmission power and the channel status.

It should be noted that, the device on the user equipment side describedwith reference to FIG. 2 corresponds to the device on the base stationside described with reference to FIG. 1, thus contents not described indetail here may be referred to foregoing description at correspondingpositions and are not described repeatedly here. Next, a signalinginteraction flow for downlink transmission according to an embodiment ofthe present disclosure is described in conjunction with the devices onthe base station side and on the user equipment side described above.

FIG. 3 is a flow diagram showing an example of a signaling interactionprocess for downlink transmission according to an embodiment of thepresent disclosure.

As shown in FIG. 3, in step S31, a base station predefines a layer-timecode matrix based on the number of data streams and the maximumretransmission count. In step S32, the base station indicates to a userequipment a data stream number corresponding thereto. In step S33, thebase station determines a layer-time code parameter for data blocktransmission this time based on a retransmission count and the datastream number, and weights modulated data blocks with the parameter. Forthe first transmission, the retransmission count may be defined to be 0.In step S34, the base station calculates transmission powers of therespective data blocks, and performs power adjustment for the weighteddata blocks. In step S35, the base station superposes the data blocksobtained after the power adjustment. In step S36, the base stationtransmits the superposed signal to the user equipment. Upon receivingthe superposed signal, the user equipment demodulates the received datablock, performs interference cancellation ranking on the received datablock and performs successive interference cancellation demodulation instep S37, and performs CRC self-checking on data obtained throughdemodulation in step S38. In step S39, in a case that the retransmissioncount is greater than 1, for a data block which is not correctlyobtained by demodulating, the user equipment performs linear mergingaccording to the layer-time code corresponding to the data block andbased on a principle of positive superposition of receiving powers, andperforms successive interference cancellation demodulation andself-checking, and then transmits a self-checking result to the basestation in step S310. In step S311, in a case of determiningretransmission for a data block is required, the base station increasesthe retransmission count, and steps S33 to S310 are repeated toretransmit the data block; otherwise, the base station resets theretransmission count to be 0, and steps S33 to S310 are repeated totransmit a new data block.

It should be noted that the above signaling interaction process may bemerely an example rather than limitation, and may be modified based onthe above description with reference to FIG. 1 and FIG. 2. For example,processing of adjusting transmission power of the data blocks in stepS34 is optional, and thus the step may be omitted. In addition, a stepof transmitting a merging indication to the user equipment from the basestation may be added, and in this case, it is unnecessary the userequipment always performs positive merging and demodulates a signalthrough non-linear interference cancellation as in step S39, but mayperform positive merging or negative merging based on the mergingindication to eliminate or weaken an interfering signal portion, therebydemodulating a data signal. For example, although the processingcoefficients are defined in a form of the layer-time code matrix, thebase station terminal may not predefine the layer-time code matrix, butprocesses a retransmitted signal based on an actual receiving condition.In practice, those skilled in the art may modify the above signalinginteraction process in other manners according to the principles of thepresent disclosure, and all of such modifications fall within the scopeof the present disclosure.

A case of downlink transmission has been described above with referenceto FIG. 1 to FIG. 3, however, the technology in the present disclosuremay be also applied to uplink transmission. A case of uplinktransmission is described below with reference to FIG. 4 to FIG. 6.

FIG. 4 is a block diagram showing a functional configuration example ofa device in a wireless communication system according to yet anotherembodiment of the present disclosure. The device may be provided in abase station or on a base station side.

As shown in FIG. 4, a device 400 according to the embodiment may includea receiving unit 402, a processing unit 404 and a transmitting unit 406.Functional configuration examples of the above units are described indetail below.

The receiving unit 402 may be configured to receive a first allocationsignal. The first allocation signal includes at least a first powersignal portion and a second power signal portion transmittedrespectively by a first user equipment and a second user equipment onsame first radio transmission resources. Specifically, the first userequipment and the second user equipment respectively transmit signals toa base station on same time-frequency resources, and the firstallocation signal received at the base station may be equivalent tosuperposition of the signals from the two user equipment.

The processing unit 404 may be configured to obtain the data from thefirst user equipment and the data from the second user equipmentaccording to the first allocation signal.

Due to the existence of interference, the processing unit 404 may notcorrectly obtain the data from the first user equipment and the datafrom the second user equipment through decoding based on only the firstallocation signal. Therefore, the transmitting unit 406 may beconfigured to transmit a retransmission request to the first userequipment and the second user equipment in a case that the processingunit 404 fails to obtain the data from at least one of the first userequipment and the second user equipment based on the first allocationsignal.

It should be understood that the base station may not transmit theretransmission request to the user equipment, data from which has beenobtained through decoding, and thus a power signal portion for the userequipment is equal to 0 in the retransmission. In addition, generallyspeaking, if data from one of the user equipment is failed to beobtained through demodulation, possibility that data from the other userequipment is obtained through demodulation is also small. Therefore, thebase station generally transmits the retransmission requests to both ofthe two user equipment, without excluding a case that the retransmissionrequest is transmitted to only one of the user equipment. For theconvenience of description, a case that the base station transmits theretransmission requests to the two user equipment is taken as an examplefor description, and a case that the base station does not transmit theretransmission request to one of the user equipment is regarded as aspecial case that a power signal portion from the one user equipment isset to be 0 in the retransmission, which is not separately describedhere.

Therefore, the receiving unit 402 may further receive a secondallocation signal, which may include at least a third power signalportion and a fourth power signal portion respectively transmitted bythe first user equipment and the second user equipment on same secondradio transmission resources in response to the retransmission request.The third power signal portion and the fourth power signal portion areobtained by respectively processing the first power signal portion andthe second power signal portion with predetermined processingcoefficients. In a case that the base station transmits theretransmission request to only one of the first user equipment and thesecond user equipment for example, the third power signal portion or thefourth power signal portion may be set to be 0.

The processing unit 404 may merge the first allocation signal and thesecond allocation signal to obtain the data from the first userequipment and the data from the second user equipment Preferably, in themerged first allocation signal and second allocation signal, the firstpower signal portion and the third power signal portion are eliminatedor weakened with respect to each other, or the second power signalportion and the fourth power signal portion are eliminated or weakenedwith respect to each other. The specific processing of obtaining thethird power signal portion and the fourth power signal portion byprocessing the first power signal portion and the second power signalportion, and eliminating an interfering signal portion through mergingoperation to thereby obtain data through demodulation may be the same asthe processing in the downlink transmission above, which is notdescribed repeatedly anymore herein.

Preferably, as described above, the processing unit 404 may be furtherconfigured to execute nonlinear interference cancellation based on aresult of the merging. In a case that the data from one of the firstuser equipment and the second user equipment is obtained through themerging operation as described above, data from the other of the firstuser equipment and the second user equipment may be derived through forexample successive interference cancellation.

Preferably, the processing unit 404 of the base station may determine atransmission power of each of the first power signal portion, the secondpower signal portion, the third power signal portion and the fourthpower signal portion based on a current radio condition, and thetransmitting unit 406 transmits power indications to the first userequipment and the second user equipment to inform the first userequipment and the second user equipment of the determined transmissionpowers, so that the first user equipment and the second user equipmentmay transmit the first power signal portion, the second power signalportion, the third power signal portion and the fourth power signalportion at respective transmission powers. It should be understood thatthe transmission powers may be determined in advance instead of beingdetermined by the base station, and in this case, the user equipment maytransmit data to the base station at the transmission powers determinedin advance.

In addition, preferably, the processing unit 404 may be furtherconfigured to determine the first radio transmission resources and thesecond radio transmission resources, and the transmitting unit 406 maybe further configured to transmit resource indications to the first userequipment and the second user equipment to indicate the first radiotransmission resources and the second radio transmission resources.Alternatively, the first user equipment and the second user equipmentmay also transmit data on radio transmission resources determined inadvance instead of being determined by the base station.

In addition, the processing unit 404 may be further configured todetermine the predetermined processing coefficients, and thetransmitting unit 406 may transmit the determined predeterminedprocessing coefficients to the first user equipment and the second userequipment, so that the first user equipment and the second userequipment process the first power signal portion and the second powersignal portion with the predetermined processing coefficients to obtainthe third power signal portion and the fourth power signal portion. Inpractice, the predefined processing coefficients may be of coursedetermined in advance, instead of being determined by the base station.

Preferably, the power indications, the resource indications and thepredetermined processing coefficients described above may be containedin uplink grant signaling (UL grant) transmitted by the base stationthrough PDCCH.

Next, a functional configuration example of a device in a wirelesscommunication system according to still another embodiment of thepresent disclosure is described with reference to FIG. 5. FIG. 5 is ablock diagram showing a functional configuration example of a device ina wireless communication system according to still another embodiment ofthe present disclosure. The device may be provided in a user equipmentor on a user equipment side.

As shown in FIG. 5, a device 500 according to the embodiment may includea transmitting unit 502, a receiving unit 504 and a processing unit 506.Functional configuration examples of the above units are described indetail below.

The transmitting unit 502 may be configured to transmit a first powersignal portion to a base station at a first transmission power on firstradio transmission resources, which are the same as radio transmissionresources on which a second user equipment transmits a second powersignal portion, and the second user equipment may for example transmitthe second power signal portion at a second transmission power. In thisway, a signal received by the base station may be equivalent to asuperposed signal obtained by superposing the first power signal portionand the second power signal portion.

The receiving unit 504 may be configured to receive a retransmissionrequest from the base station. In a case that the base station fails toobtain data from at least one of the first user equipment and the seconduser equipment based on the above superposed signal obtained throughsuperposition, the base station may transmit a retransmission request tothe first user equipment and the second user equipment.

The processing unit 506 may be configured to process, in response to theretransmission request, the first power signal portion with apredetermined processing coefficient to obtain a third power signalportion. Similarly, the second user equipment may also process, inresponse to the retransmission request, the second power signal portionwith a predetermined processing coefficient to obtain a fourth powersignal portion.

The transmitting unit 504 may be further configured to transmit thethird power signal portion to the base station at a third transmissionpower on second radio transmission resources, which are the same asradio transmission resources on which the second user equipmenttransmits the fourth power signal portion. Thus, the base station maymerge the signals in two transmissions to eliminate an interferingsignal portion from other user equipment. That is, after performingmerging by the base station, the first power signal portion and thethird power signal portion are weakened or eliminated with respect toeach other, or the second power signal portion and the fourth powersignal portion are weakened or eliminated with respect to each other.

As described above, the base station may determine the power fortransmitting a data signal, the radio transmission resources fortransmitting the data signal and the predetermined processingcoefficients for processing a retransmitted signal of the userequipment. The first transmission power and the third transmission powerdescribed above may be contained in a power indication from the basestation, the first radio transmission resources and the second radiotransmission resources may be contained in a resource indication fromthe base station, and the power indication, the resource indication andthe predetermined processing coefficients may be contained in uplinkgrant signaling transmitted by the base station through PDCCH.

It should be understood that except for the contents described above,the functional configuration examples of the device at the base stationand the device at the user equipment in the case of uplink transmissiondescribed here with reference to FIG. 4 and FIG. 5 are similar tofunctional configuration examples of the device at the base station andthe device at the user equipment in the case of downlink transmissiondescribed above with reference to FIG. 1 and FIG. 2 in terms of manyaspects, for example, how to process the retransmitted signal andeliminate interference through merging operation and the like, thus thecontents not described in detail here may be referred to foregoingdescription at corresponding positions, and are not described repeatedlyhere.

A signaling interaction flow for uplink transmission is described nextwith conjunction with the device at the base station and the device atthe user equipment described above. FIG. 6 is a flow diagram showing anexample of a signaling interaction process for uplink transmissionaccording to an embodiment of the present disclosure.

As shown in FIG. 6, in step S61, a base station predefines a layer-timecode matrix. In step S62, the base station indicates to a user equipmenta data stream number corresponding thereto. The base station calculatesa transmission power for the user equipment to transmit a data block instep S63, and indicates the transmission power to the user equipment instep S64. In step S65, the user equipment determines a layer-time codeparameter for transmitting the data block this time based on aretransmission count and the data stream number, and weights themodulated data block with the layer-time code parameter. For the firsttransmission, a retransmission count may be set to be 0. Then, the userequipment performs power adjustment for the weighted data block based ona transmission power indication from the base station in step S66, andtransmits the data block to the base station in step S67. The basestation demodulates the received data block and performs interferencecancellation ranking on the received data block and performs successiveinterference cancellation demodulation in step S68, and performsself-checking on the demodulated data in step S69. In step S610, in acase that the retransmission count is greater than 1, for a data blockwhich is not correctly obtained by demodulating, the user equipmentperforms linear merging according to the layer-time code correspondingto the data block and based on a principle of positive superposition ofreceiving powers, and performs successive interference cancellationdemodulation. In step S611, in a case of determining that retransmissionfor the data block is required, the base station increases theretransmission count, and steps S63 to S610 are repeated so that theuser equipment retransmits the data block; otherwise, the base stationresets the retransmission number to be 0, and steps S63 to S610 arerepeated so that the user equipment transmits a new data block.

It should be understood that, as described above, similar to the case ofdownlink transmission, the above signaling interaction process is onlyan example rather than limitation, and those skilled in the art maymodify the signaling interaction process according to principles of thepresent disclosure. For example, processing in step S63 is optional, andthe transmission power for the user equipment to transmit a data blockmay be also predetermined. For example, it is not necessary thatpositive merging is always performed for signals transmitted multipletimes as in step S610, and positive merging or negative merging may beexecuted according to actual needs to reduce calculation load. Inpractice, those skilled in the art may conceive of other variations ofthe above signaling interaction process according to the principles ofthe present disclosure, which are not enumerated here anymore, and allof such variations are regarded to fall within the scope of the presentdisclosure.

It should be understood that although the functional configurationexamples of the devices in the wireless communication system accordingto the embodiments of the present disclosure and the interaction processexamples between communication devices are described above, these areonly examples rather than restrictions. Those skilled in the art maymodify the above embodiments according to principles of the presentdisclosure, for example, add, delete and/or combine functional modulesin the embodiments, and all of such modifications fall within the scopeof the present disclosure.

Corresponding to the above device embodiments, methods in a wirelesscommunication system are further provided according to an embodiment ofthe present disclosure. Process examples of methods in a wirelesscommunication system according to embodiments of the present disclosureare described in detail below with reference to FIG. 7 to FIG. 10.

FIG. 7 is a flow diagram showing a process example of a method in awireless communication system according to an embodiment of the presentdisclosure. The method may be executed on the base station side.

As shown in FIG. 7, the method according to the embodiment may include atransmitting step S702, a receiving step S704 and a processing stepS706. Processing in each of the steps is described in detail below.

First, in the transmitting step S702, a first allocation signalsuperposed using superposition coding may be transmitted to multipleuser equipment including at least a first user equipment and a seconduser equipment. The first allocation signal includes at least a firstpower signal portion for the first user equipment and a second powersignal portion for the second user equipment. It can be known accordingto the principle of superposition coding that a transmission power ofthe first power signal portion may be greater than or less than atransmission power of the second power signal portion based on radioconditions of the first user equipment and the second user equipment.

In a case that at least one of the first user equipment and the seconduser equipment fails to obtain the data therefor based on the firstallocation signal, at least one of the first user equipment and thesecond user equipment may transmit a retransmission request to the basestation to request retransmitting the signal. In the receiving stepS704, a retransmission request fed back from at least one of the rustuser equipment and the second user equipment may be received.

In the processing step S706, the first power signal portion and thesecond power signal portion may be processed with predeterminedprocessing coefficients in response to the retransmission request toobtain a second allocation signal. Preferably, the predeterminedprocessing coefficients may be determined based on a Hadamard matrix,that is, the predetermined processing coefficient may be the “layer-timecode matrix” described above.

After obtaining the second allocation signal in the processing stepS706, the second allocation signal may be further transmitted to thefirst user equipment and the second user equipment in the transmittingstep S702, so that the first user equipment and the second userequipment merge the first allocation signal and the second allocationsignal to respectively obtain data for the first user equipment and datafor the second user equipment.

According to the above processing, in the merged first allocation signaland second allocation signal, one of the first power signal portion andthe second power signal portion is weakened or eliminated, therebygreatly reducing interference from other user equipment whendemodulating the data, and greatly improving a possibility ofsuccessfully obtaining data through demodulation.

It should be noted that the method described here corresponds to thedevice embodiment in the wireless communication system described abovewith reference to FIG. 1, thus contents not described in detail here maybe referred to the foregoing description at corresponding positions andare not repeated here anymore.

FIG. 8 is a flow diagram showing a process example of a method in awireless communication system according to another embodiment of thepresent disclosure. The method may be executed on the user equipmentside.

As shown in FIG. 8, the method according to the embodiment may include areceiving step S802, a processing step S804 and a transmitting stepS806. Processing in each of the steps is described in detail below.

In the receiving step S802, a first allocation signal from a basestation may be received, the first allocation signal being superposed bysuperposition coding and including at least a first power signal portionfor the first user equipment and a second power signal portion for thesecond user equipment.

In the processing step S804, data for the first user equipment may beobtained based on the first allocation signal.

In the transmitting step S806, a retransmission request may betransmitted to the base station in a case that the data for the firstuser equipment is failed to be obtained based on the first allocationsignal.

Upon receiving the retransmission request, the base station mayretransmit to the user equipment which transmits the retransmissionrequest the data therefor, or may retransmit a superposed signalobtained by superposition coding to the two user equipment. In thereceiving step S802, a second allocation signal is further received fromthe base station, the second allocation signal being obtained byprocessing, by the base station, the first power signal portion and thesecond power signal portion with predetermined processing coefficientsin response to the retransmission request fed back from at least one ofthe first user equipment and the second user equipment. It should beunderstood that, in a case that the base station retransmits data onlyto the user equipment which transmits the retransmission request, a datasignal portion related to other user equipment in the second allocationsignal may be regarded to be 0.

Upon receiving the second allocation signal, in the processing stepS804, the first allocation signal and the second allocation signal maybe merged to obtain data for the first user equipment. Similarly,similar processing may be performed at the second user equipment toobtain data for the second user equipment.

It should be noted that, the method described here corresponds to thedevice embodiment in the wireless communication system described abovewith reference to FIG. 2, thus contents not described in detail here maybe referred to the foregoing description at corresponding positions andare not repeated here anymore.

The methods described above with reference to FIG. 7 and FIG. 8 aremethods executed respectively at the base station and the user equipmentin the downlink transmission, and methods executed respectively at thebase station and the user equipment in the uplink transmission aredescribed below.

FIG. 9 is a flow diagram showing a process example of a method in awireless communication system according to yet another embodiment of thepresent disclosure. The method may be executed on the base station side.

As shown in FIG. 9, the method according to the embodiment may include areceiving step S902, a processing step S904 and a transmitting stepS906. Processing in each of the steps is described in detail below.

In the receiving step S902, a first allocation signal may be received,the first allocation signal including at least a first power signalportion and a second power signal portion transmitted respectively by afirst user equipment and a second user equipment on same first radiotransmission resources. Since the first user equipment and the seconduser equipment respectively transmit data thereof to the base station onthe same time-frequency resources, the signal received by the basestation may be equivalent to data obtained by performing superpositioncoding on the data from the two user equipment.

In the processing step S904, data from the user equipment and data fromthe second user equipment may be obtained based on the first allocationsignal.

In the transmitting step S906, in a case that data from at least one ofthe first user equipment and the second user equipment is failed to beobtained based on the first allocation signal, a retransmission requestis transmitted to the first user equipment and the second userequipment. It is assumed here that the base station transmits theretransmission request to both of the two user equipment, and a casethat the base station transmits the retransmission request to only theuser equipment for which the data is not demodulated may be regarded asa special case that data retransmitted from the user equipment is 0.

In response to the retransmission request from the base station, thefirst user equipment and the second user equipment may retransmit datato the base station on same time-frequency resources. In the receivingstep S902, the second allocation signal is further received, the secondallocation signal including at least a third power signal portion and afourth power signal portion transmitted by the first user equipment andthe second user equipment on the same second radio transmissionresources in response to the retransmission request, the third powersignal portion and the fourth power signal portion being obtained byprocessing the first power signal portion and the second power signalportion with predetermined processing coefficients. The predeterminedprocessing coefficients may be predetermined, or may be determined bythe base station and then informed to the user equipment. Upon receivingthe second allocation signal, in the processing step S904, the firstallocation signal and the second allocation signal may be merged toobtain the data from the first user equipment and the data from thesecond user equipment.

It should be noted that, the method described here corresponds to thedevice embodiment in the wireless communication system described withreference to FIG. 4, thus contents not described in detail here may bereferred to the foregoing description at corresponding positions and arenot repeated here anymore.

FIG. 10 is a flow diagram showing a process example of a method in awireless communication system according to still another embodiment ofthe present disclosure. The method may be executed on the user equipmentside.

As shown in FIG. 10, the method according to the embodiment may includea transmitting step S1002, a receiving step S1004 and a processing stepS1006. Processing in each of the steps is described in detail below.

In the transmitting step S1002, a first power signal portion may betransmitted to a base station at a first transmission power on firstradio transmission resources, which are the same as radio transmissionresources on which a second user equipment transmits a second powersignal portion. That is, the first user equipment and the second userequipment transmit data thereof to the base station on the sametime-frequency resources.

In the receiving step S1004, a retransmission request may be receivedfrom the base station.

In the processing step S1006, the first power signal portion may beprocessed with a predetermined processing coefficient in response to theretransmission request to obtain a third power signal portion.Similarly, the second user equipment may process the second power signalportion with a predetermined processing coefficient in response to theretransmission request to obtain a fourth power signal portion.

In the transmitting step S1002, the third power signal portion may betransmitted to the base station at a third transmission power on secondradio transmission resources, which are the same as radio transmissionresources on which the second user equipment transmits the fourth powersignal portion. That is, the first user equipment and the second userequipment transmit the third power signal portion and the fourth powersignal portion to the base station on the same time-frequency resources.Thus, the base station may merge the signals transmitted multiple timesto weaken or eliminate interference from other user equipment, so as tosuccessfully obtain the user data by demodulating.

It should be understood that the transmission powers for transmittingsignals, the radio transmission resources and the predefined processingcoefficients used by the respective user equipment may be determined atthe base station, and are informed to the user equipment by the basestation through for example uplink grant signaling.

It should be noted that the method described here corresponds to thedevice embodiment in the wireless communication system described abovewith reference to FIG. 5, thus contents not described in detail here maybe referred to the foregoing description at corresponding positions andare not repeated here anymore.

It should be understood that although the process examples of themethods in the wireless communication system according to theembodiments of the present disclosure are described above, these areonly examples rather than restrictions. Those skilled in the art canmodify the above embodiments according to principles of the presentdisclosure, for example, add, delete or combine steps in theembodiments, and all of such modifications fall within the scope of thepresent disclosure.

In addition, it should be noted that, although the process examples ofthe methods in the wireless communication system according to theembodiments of the present disclosure are described in an order shown inthe flow diagrams in the drawings and the above description, anexecution order in the methods according to the present disclosure isnot limited thereto, and the processing may be executed in parallel oras required.

According to the embodiments of the devices and the methods in thewireless communication system described above, a retransmitted signal inthe superposition transmission is processed to weaken or eliminateinterference caused by transmission with respect to other userequipment, thereby greatly improving a possibility of successfullyobtaining data through demodulation while improving throughput ofsuperposition transmission.

In addition, an electronic device is further provided according to anembodiment of the present disclosure, which may include a transceiverand one or more processors. The one or more processors may be configuredto execute the methods or functions of the units in the wirelesscommunication system according to the embodiments of the presentdisclosure described above.

It is to be understood that the machine-executable instructions in astorage medium and a program product according to an embodiment of thepresent disclosure may be configured to perform a method correspondingto the above apparatus embodiment, and thus the contents which are notdescribed in detail herein may be referred to the foregoing descriptionat corresponding positions and are not repeated herein.

Accordingly, a storage medium on which the above program product storingmachine-executable instructions is carried is also included in thepresent disclosure. The storage medium includes but not limited to afloppy disk, an optical disk, a magneto-optical disk, a storage card, amemory rod and the like.

Furthermore, it shall be noted that the foregoing series of processesand devices can also be embodied in software and/or firmware. In thecase of being embodied in software and/or firmware, a programconstituting the software is installed from a storage medium or anetwork to a computer with a dedicated hardware structure, e.g., ageneral purpose personal computer 1100 illustrated in FIG. 11, which canperform various functions when various programs are installed thereon.FIG. 11 is a block diagram showing an exemplary structure of a personalcomputer as an information processing device used in an embodiment ofthe present disclosure.

In FIG. 11, a Central Processing Unit (CPU) 1101 performs variousprocesses according to a program stored in a Read Only Memory (ROM) 1102or loaded from a storage portion 1108 into a Random Access Memory (RAM)1103 in which data required when the CPU 1101 performs the variousprocesses is also stored as needed.

The CPU 1101, the ROM 1102 and the RAM 1103 are connected to each othervia a bus 1104 to which an input/output interface 1105 is alsoconnected.

The following components are connected to the input/output interface1105: an input portion 1106 including a keyboard, a mouse, etc.; anoutput portion 1107 including a display, e.g., a Cathode Ray Tube (CRT),a Liquid Crystal Display (LCD), etc., a speaker, etc.; a storage portion1108 including a hard disk, etc.; and a communication portion 1109including a network interface card, e.g., an LAN card, a modem, etc. Thecommunication portion 1109 performs a communication process over anetwork, e.g., the Internet.

A drive 1110 is also connected to the input/output interface 1105 asneeded. A removable medium 1111, e.g., a magnetic disk, an optical disk,an magneto optical disk, a semiconductor memory, etc., can be installedon the drive 1110 as needed so that a computer program fetched therefromcan be installed into the storage portion 1108 as needed.

In the case that the foregoing series of processes are performed insoftware, a program constituting the software is installed from anetwork, e.g., the Internet, etc., or a storage medium, e.g., theremovable medium 1111, etc.

Those skilled in the art shall appreciate that such a storage mediumwill not be limited to the removable medium 1111 illustrated in FIG. 11in which the program is stored and which is distributed separately fromthe apparatus to provide a user with the program. Examples of theremovable medium 1111 include a magnetic disk (including a Floppy Disk(a registered trademark)), an optical disk (including Compact Disk-ReadOnly memory (CD-ROM) and a Digital Versatile Disk (DVD)), a magnetooptical disk (including a Mini Disk (MD) (a registered trademark)) and asemiconductor memory. Alternatively the storage medium can be the ROM1102, a hard disk included in the storage portion 1108, etc., in whichthe program is stored and which is distributed together with theapparatus including the same to the user.

The application examples of the present disclosure are described nextwith reference to FIG. 12 to FIG. 14.

Application Example Regarding eNB First Application Example

FIG. 12 is a block diagram showing a first example of a schematicconfiguration of an eNB to which the technology according to the presentdisclosure may be applied. An eNB 1200 includes one or more antennas1210 and a base station apparatus 1220. The base station apparatus 1220and each antenna 1210 may be connected to each other via an RF cable.

Each of the antennas 1210 includes a single or multiple antenna elements(such as to multiple antenna elements included in an MIMO antenna), andis used for the base station apparatus 1220 to transmit and receiveradio signals. The eNB 1200 may include the multiple antennas 1210, asillustrated in FIG. 12. For example, the multiple antennas 1210 may becompatible with multiple frequency bands used by the eNB 1200. AlthoughFIG. 12 illustrates the example in which the eNB 1200 includes themultiple antennas 1210, the eNB 1200 may also include a single antenna1210.

The base station apparatus 1220 includes a controller 1221, a memory1222, a network interface 1223, and a radio communication interface1225.

The controller 1221 may be, for example, a CPU or a DSP, and operatesvarious functions of a higher layer of the base station apparatus 1220.For example, the controller 1221 generates a data packet from data insignals processed by the radio communication interface 1225, andtransfers the generated packet via the network interface 1223. Thecontroller 1221 may bundle data from multiple base band processors togenerate the bundled packet, and transfer the generated bundled packet.The controller 1221 may have logical functions of performing controlsuch as radio resource control, radio bearer control, mobilitymanagement, admission control, and scheduling. The control may beperformed in cooperation with an eNB or a core network node in thevicinity. The memory 1222 includes RAM and ROM, and stores a programthat is executed by the controller 1221, and various types of controldata (such as a terminal list, transmission power data, and schedulingdata).

The network interface 1223 is a communication interface for connectingthe base station apparatus 1220 to a core network 1224. The controller1221 may communicate with a core network node or another eNB via thenetwork interface 1223. In that case, the eNB 1200, and the core networknode or the other eNB may be connected to each other through a logicalinterface (such as an SI interface and an X2 interface). The networkinterface 1223 may also be a wired communication interface or a radiocommunication interface for radio backhaul. If the network interface1223 is a radio communication interface, the network interface 1223 mayuse a higher frequency band for radio communication than a frequencyband used by the radio communication interface 1225.

The radio communication interface 1225 supports any cellularcommunication scheme such as Long Term Evolution (LTE) and LTE-Advanced,and provides radio connection to a terminal positioned in a cell of theeNB 1200 via the antenna 1210. The radio communication interface 1225may typically include, for example, a baseband (BB) processor 11226 andan RF circuit 1227. The BB processor 1226 may perform, for example,encoding/decoding, modulating/demodulating, andmultiplexing/demultiplexing, and performs various types of signalprocessing of layers (such as L1, medium access control (MAC), radiolink control (RLC), and a packet data convergence protocol (PDCP)). TheBB processor 1226 may have a part or all of the above-described logicalfunctions instead of the controller 1221. The BB processor 1226 may be amemory that stores a communication control program, or a module thatincludes a processor and a related circuit configured to execute theprogram. Updating the program may allow the functions of the BBprocessor 1226 to be changed. The module may be a card or a blade thatis inserted into a slot of the base station apparatus 1220.Alternatively, the module may also be a chip that is mounted on the cardor the blade. Meanwhile, the RF circuit 1227 may include, for example, amixer, a filter, and an amplifier, and transmits and receives radiosignals via the antenna 1210.

The radio communication interface 1225 may include the multiple BBprocessors 1226, as illustrated in FIG. 12. For example, the multiple BBprocessors 1226 may be compatible with multiple frequency bands used bythe eNB 1200. The radio communication interface 1225 may include themultiple RF circuits 1227, as illustrated in FIG. 12. For example, themultiple RF circuits 1227 may be compatible with multiple antennaelements. Although FIG. 12 illustrates the example in which the radiocommunication interface 1225 includes the multiple BB processors 1226and the multiple RF circuits 1227, the radio communication interface1225 may also include a single BB processor 1226 or a single RF circuit1227.

Second Application Example

FIG. 13 is a block diagram illustrating a second example of a schematicconfiguration of an eNB to which the technology of the presentdisclosure may be applied. An eNB 1330 includes one or more antennas1340, a base station apparatus 1350, and an RRH 1360. Each antenna 1340and the RRH 1360 may be connected to each other via an RF cable. Thebase station apparatus 1350 and the RRH 1360 may be connected to eachother via a high speed line such as an optical fiber cable.

Each of the antennas 1340 includes a single or multiple antenna elements(such as multiple antenna elements included in an MIMO antenna), and isused for the RRH 1360 to transmit and receive radio signals. The eNB1330 may include the multiple antennas 840, as illustrated in FIG. 13.For example, the multiple antennas 1340 may be compatible with multiplefrequency bands used by the eNB 1330. Although FIG. 13 illustrates theexample in which the eNB 1330 includes the multiple antennas 1340, theeNB 1330 may also include a single antenna 1340.

The base station apparatus 1350 includes a controller 1351, a memory1352, a network interface 1353, a radio communication interface 1355,and a connection interface 1357. The controller 1351, the memory 1352,and the network interface 1353 are the same as the controller 1221, thememory 1222, and the network interface 1223 described with reference toFIG. 12.

The radio communication interface 1355 supports any cellularcommunication scheme such as LTE and LTE-Advanced, and provides radiocommunication to a terminal positioned in a sector corresponding to theRRH 1360 via the RRH 1360 and the antenna 1340. The radio communicationinterface 1355 may typically include, for example, a BB processor 1356.The BB processor 1356 is the same as the BB processor 1226 describedwith reference to FIG. 12, except the BB processor 1356 is connected tothe RF circuit 1364 of the RRH 1360 via the connection interface 1357.The radio communication interface 1355 may include the multiple BBprocessors 1356, as illustrated in FIG. 13. For example, the multiple BBprocessors 1356 may be compatible with multiple frequency bands used bythe eNB 1330. Although FIG. 13 illustrates the example in which theradio communication interface 1355 includes the multiple BB processors1356, the radio communication interface 1355 may also include a singleBB processor 1356.

The connection interface 1357 is an interface for connecting the basestation apparatus 1350 (radio communication interface 1355) to the RRH1360. The connection interface 1357 may also be a communication modulefor communication in the above-described high speed line that connectsthe base station apparatus 1350 (radio communication interface 1355) tothe RRH 1360.

The RRH 1360 includes a connection interface 1361 and a radiocommunication interface 1363.

The connection interface 1361 is an interface for connecting the RRH1360 (radio communication interface 1363) to the base station apparatus1350. The connection interface 1361 may also be a communication modulefor communication in the above-described high speed line.

The radio communication interface 1363 transmits and receives radiosignals via the antenna 1340. The radio communication interface 1363 maytypically include, for example, the RF circuit 1364. The RF circuit 1364may include, for example, a mixer, a filter, and an amplifier, andtransmits and receives radio signals via the antenna 1340. The radiocommunication interface 1363 may include multiple RF circuits 1364, asillustrated in FIG. 13. For example, the multiple RF circuits 1364 maysupport multiple antenna elements. Although FIG. 13 illustrates theexample in which the radio communication interface 1363 includes themultiple RF circuits 1364, the radio communication interface 1363 mayalso include a single RF circuit 1364.

In the eNB 1200 and the eNB 1300 shown in FIG. 12 and FIG. 13, thetransmitting unit and the receiving unit described by using FIG. 1 andFIG. 4 may be implemented by the radio communication interface 1225 andthe radio communication interface 1355 and/or the radio communicationinterface 1363. At least a part of the functions of the processing unitin the device on the base station side in the wireless communicationsystem may also be implemented with the controller 1221 and thecontroller 1351.

[Application Example Regarding User Equipment]

FIG. 14 is a block diagram illustrating an example of a schematicconfiguration of a smartphone 1400 to which the technology of thepresent disclosure may be applied. The smartphone 1400 includes aprocessor 1401, a memory 1402, a storage 1403, an external connectioninterface 1404, a camera 1406, a sensor 1407, a microphone 1408, aninput device 1409, a display device 1410, a speaker 1411, a radiocommunication interface 1412, one or more antenna switches 1415, one ormore antennas 1416, a bus 1417, a battery 1418, and an auxiliarycontroller 1419.

The processor 1401 may be for example a CPU or a system on chip (SoC),and controls functions of an application layer and another layer of thesmartphone 1400. The memory 1402 includes a RAM and a ROM, and stores aprogram executed by the processor 1401, and data. The storage 1403 mayinclude a storage medium such as a semiconductor memory and a hard disk.The external connection interface 1404 is an interface for connecting anexternal device such as a memory card and a universal serial bus (USB)device to the smartphone 1400.

The camera 1406 includes an image sensor such as a charge-coupled device(CCD) and a complementary metal oxide semiconductor (CMOS), andgenerates a captured image. The sensor 1407 may include a group ofsensors such as a measurement sensor, a gyroscope sensor, a geomagneticsensor and an acceleration sensor. The microphone 1408 converts soundsinputted to the smartphone 1400 to audio signals. The input device 1409includes, for example, a touch sensor configured to detect touch onto ascreen of the display device 1410, a keypad, a keyboard, a button or aswitch, and receives an operation or information inputted from the user.The display device 1410 includes a screen such as a liquid crystaldisplay (LCD) and an organic light-emitting diode (OLED) display, anddisplays an output image of the smartphone 1400. The speaker 1411converts audio signals outputted from the smartphone 1400 into sounds.

The radio communication interface 1412 supports any cellularcommunication scheme such as LTE and LTE-advanced, and performs radiocommunication. The radio communication interface 1412 may typicallyinclude for example a BB processor 1413 and an RF circuit 1414. The BBprocessor 1413 may execute for example encoding/decoding,modulation/demodulation and multiplexing/demultiplexing, and executevarious types of signal processing for radio communication. Meanwhile,the RF circuit 1414 may include for example a mixer, a filter and anamplifier, and transmits and receives a radio signal via the antenna1416. The radio communication interface 1412 may be a one chip modulehaving the BB processor 1413 and the RF circuit 1414 integrated thereon.As shown in FIG. 14, the radio communication interface 1412 may includemultiple BB processors 1413 and multiple RF circuits 1414. Although FIG.14 illustrates the example in which the radio communication interface1412 includes multiple BB processors 1413 and multiple RF circuits 1414,the radio communication interface 1412 may also include a single BBprocessor 1413 and a single RF circuit 1414.

Furthermore, in addition to the cellular communication scheme, the radiocommunication interface 1412 may support other types of radiocommunication scheme, such as a short-distance wireless communicationscheme, a near field communication scheme and a wireless local areanetwork (LAN) scheme. In this case, the radio communication interface1412 may include the BB processor 1413 and the RF circuit 1414 for eachradio communication scheme.

Each of the antenna switches 1415 switches connection destinations ofthe antennas 1416 among multiple circuits (for example, circuits fordifferent radio communication schemes) included in the radiocommunication interface 1412.

Each of the antennas 1416 includes a single or multiple antenna elements(for example, multiple antenna elements included in the MIMO antenna),and is used for the radio communication interface 1412 to transmit andreceive radio signals. As shown in FIG. 14, the smartphone 1400 mayinclude multiple antennas 1416. Although FIG. 14 illustrates the examplein which the smartphone 1400 includes multiple antennas 1416, thesmartphone 1400 may include a single antenna 1416.

In addition, the smartphone 1400 may include an antenna 1416 for eachradio communication scheme. In this case, the antenna switches 1415 maybe omitted from the configuration of the smartphone 1400.

The bus 1417 connects the processor 1401, the memory 1402, the storage1403, the external connection interface 1404, the camera 1406, thesensor 1407, the microphone 1408, the input device 1409, the displaydevice 1410, the speaker 1411, the radio communication interface 1412and the auxiliary controller 1419 to each other. The battery 1418supplies power to blocks in the smartphone 1400 shown in FIG. 14 viafeeder lines, which are partially shown as dashed lines in the figure.The auxiliary controller 1419 operates a minimum necessary function ofthe smartphone 1400, for example, in a sleep mode.

In the smartphone 1400 shown in FIG. 14, the transmitting unit and thereceiving unit described by using FIG. 2 and FIG. 5 may be implementedby the radio communication interface 1412. At least a part of thefunctions of the processing unit in the device on the user equipmentside described above may be implemented by the processor 1401 or theauxiliary controller 1419.

Preferred embodiments of the present disclosure are described withreference to the drawings above, but the present disclosure is of coursenot limited to the above examples. Those skilled in the art may makevarious alternations and modifications within the scope of the appendedclaims, and it should be understood that these alternations andmodifications naturally fall within the technical scope of the presentdisclosure.

For example, in the above embodiments, multiple functions included inone unit may be implemented by separated devices. Alternatively, in theabove embodiments, multiple functions implemented by multiple units maybe implemented by separated devices. In addition, one of the abovefunctions may be implemented by multiple units. As a matter of course,such configuration is included in the technical scope of the presentdisclosure.

In the description, steps described in the flowcharts not only includeprocessing performed chronically in the order described, but alsoinclude processing performed concurrently or separately but notnecessarily chronically. In addition, even if in steps performedchronically, as a matter of course, the order may be also changedappropriately.

1. A device in a wireless communication system, the device comprising: atransmitting unit configured to transmit a first allocation signalsuperposed using superposition coding to a plurality of user equipmentcomprising at least a first user equipment and a second user equipment,wherein the first allocation signal comprises at least a first powersignal portion for the first user equipment and a second power signalportion for the second user equipment; a receiving unit configured toreceive a retransmission request fed back from at least one of the firstuser equipment and the second user equipment; and a processing unitconfigured to process, in response to the retransmission request, thefirst power signal portion and the second power signal portion withpredetermined processing coefficients to obtain a second allocationsignal, wherein the transmitting unit is further configured to transmitthe second allocation signal to the first user equipment and the seconduser equipment, so that the first user equipment and the second userequipment merge the first allocation signal and the second allocationsignal to obtain data for the first user equipment and data for thesecond user equipment.
 2. The device according to claim 1, wherein inthe merged first allocation signal and second allocation signal, one ofthe first power signal portion and the second power signal portion isweakened or eliminated.
 3. (canceled)
 4. The device according claim 1,wherein the transmitting unit is further configured to transmit to thefirst user equipment and the second user equipment a merging indicationindicating how to merge, so that the first user equipment and the seconduser equipment merge the first allocation signal and the secondallocation signal based on the merging indication. 5-7. (canceled) 8.The device according to claim 1, wherein the predetermined processingcoefficients are determined based on a Hadamard matrix.
 9. A device in awireless communication system, the device comprising: a receiving unitconfigured to receive a first allocation signal from a base station,wherein the first allocation signal is superposed using superpositioncoding and comprises at least a first power signal portion for a firstuser equipment and a second power signal portion for a second userequipment; a processing unit configured to obtain data for the firstuser equipment according to the first allocation signal; and atransmitting unit configured to transmit, in a case that the processingunit fails to obtain the data for the first user equipment according tothe first allocation signal, a retransmission request to the basestation, wherein the receiving unit is further configured to receive asecond allocation signal from the base station, the second allocationsignal being obtained by processing, by the base station, the firstpower signal portion and the second power signal portion withpredetermined processing coefficients in response to the retransmissionrequest fed back from at least one of the first user equipment and thesecond user equipment, and wherein the processing unit is furtherconfigured to merge the first allocation signal and the secondallocation signal to obtain the data for the first user equipment. 10.The device according to claim 9, wherein in the merged first allocationsignal and second allocation signal, one of the first power signalportion and the second power signal portion is weakened or eliminated.11. The device according to claim 9, wherein the receiving unit isfurther configured to receive from the base station a merging indicationindicating how to merge, and the processing unit is further configuredto merge the first allocation signal and the second allocation signalbased on the merging indication.
 12. The device according to claim 11,wherein the merging indication is contained in high layer signaling orphysical layer signaling.
 13. The device according to claim 9, whereinthe processing unit is further configured to merge the first allocationsignal and the second allocation signal to enhance a higher one of thefirst power signal portion and the second power signal portion.
 14. Thedevice according to claim 9, wherein the processing unit is furtherconfigured to merge the first allocation signal and the secondallocation signal to enhance the first power signal portion for thefirst user equipment.
 15. (canceled)
 16. The device according to claim9, wherein the processing unit is further configured to performnon-linear interference cancellation based on a result of the merging.17. A device in a wireless communication system, the device comprising:a receiving unit configured to receive a first allocation signal,wherein the first allocation signal comprises at least a first powersignal portion and a second power signal portion transmittedrespectively by a first user equipment and a second user equipment onsame first radio transmission resources; a processing unit configured toobtain data from the first user equipment and data from the second userequipment according to the first allocation signal; and a transmittingunit configured to transmit, in a case that the processing unit fails toobtain the data from at least one of the first user equipment and thesecond user equipment according to the first allocation signal, aretransmission request to the first user equipment and the second userequipment, wherein the receiving unit is further configured to receive asecond allocation signal, the second allocation signal comprising atleast a third power signal portion and a fourth power signal portiontransmitted respectively by the first user equipment and the second userequipment on same second radio transmission resources in response to theretransmission request, the third power signal portion and the fourthpower signal portion being obtained by respectively processing the firstpower signal portion and the second power signal portion withpredetermined processing coefficients, and wherein the processing unitis further configured to merge the first allocation signal and thesecond allocation signal to obtain the data from the first userequipment and the data from the second user equipment.
 18. The deviceaccording to claim 17, wherein in the merged first allocation signal andsecond allocation signal, the first power signal portion and the thirdpower signal portion are weakened or eliminated with respect to eachother, or the second power signal portion and the fourth power signalportion are weakened or eliminated with respect to each other.
 19. Thedevice according to claim 17, wherein the processing unit is furtherconfigured to determine a transmission power of each of the first powersignal portion, the second power signal portion, the third power signalportion and the fourth power signal portion, and wherein thetransmitting unit is further configured to transmit a power indicationto the first user equipment and the second user equipment to indicatethe determined transmission powers.
 20. (canceled)
 21. The deviceaccording to claim 19, wherein the processing unit is further configuredto determine the predetermined processing coefficients, and thetransmitting unit is further configured to transmit the predeterminedprocessing coefficients to the first user equipment and the second userequipment.
 22. The device according to claim 21, wherein the powerindication, a resource indication and the predetermined processingcoefficients are contained in uplink grant signaling.
 23. The deviceaccording to claim 17, wherein the processing unit is further configuredto perform non-linear interference cancellation based on a result of themerging.
 24. A device in a wireless communication system, the devicecomprising: a transmitting unit configured to transmit a first powersignal portion to a base station at a first transmission power on firstradio transmission resources, which are the same as radio transmissionresources on which a second user equipment transmits a second powersignal portion; a receiving unit configured to receive a retransmissionrequest from the base station; and a processing unit configured toprocess, in response to the retransmission request, the first powersignal portion with a predetermined processing coefficient to obtain athird power signal portion, wherein the transmitting unit is furtherconfigured to transmit the third power signal portion to the basestation at a third transmission power on second radio transmissionresources, which are the same as radio transmission resources on whichthe second user equipment transmits a fourth power signal portion, thefourth power signal portion being obtained by processing, by the seconduser equipment, the second power signal portion with a predeterminedprocessing coefficient in response to the retransmission request. 25.The device according to claim 24, wherein the first transmission powerand the third transmission power are contained in a power indicationreceived from the base station.
 26. (canceled)
 27. The device accordingto claim 25, wherein the power indication, a resource indication and thepredetermined processing coefficient are contained in uplink grantsignaling. 28-31. (canceled)